Our research focuses on ultracold gases of atoms and molecules. Our experiments use laser cooling, magnetic trapping, and evaporative cooling to reach temperatures below one microKelvin, where quantum statistics dominate the behavior of the atoms or molecules. We study quantum gases of fermions, as well as bosons, and explore a variety of phenomena such as Bose-Einstein condensation, Cooper pairing of fermions, superfluidity, and spin models realized with ultracold polar molecules.

Research Areas

Our group studies the interactions of bosons and fermions in a two-species quantum degenerate gas. We use bosonic Rb-87 atoms to sympathetically cool fermionic K-40 atoms. These two atom species have an interspecies Fano-Feshbach resonance that can be used to tune the interactions. Using this tool, we have created weakly bound Feshbach...

The first dilute gas Bose-Einstein condensate (BEC) was made at JILA in 1995. The gas BEC is a superfluid and is related to another superfluid, which is liquid He. For years scientists have studied superfluid liquid He, trying to understand its properties, but the fact that this state of matter occurred in a strongly interacting liquid made this...

Our group explores the physics of Fermi gases at ultracold temperatures and investigates the link between superconductivity and Bose-Einstein condensation (BEC). In late 2003, we made the first direct observation of molecular BEC. We used magnetic-field (Feshbach) scattering resonances to induce pairs of K-40 atoms to form bosonic molecules, which...

In collaboration with Jun Ye's group at JILA, we are studying an ultracold gas of polar molecules. The ultracold molecule gas is made by first cooling atoms to ultralow temperature, and then converting atoms pairwise into diatomic molecules. We use a Fano-Feshbach resonance to form very weakly bound KRb molecules from a mixture of K-40 and Rb-87...